With the proliferation of the World Wide Web and data networks such as the Internet, consumers often turn to their computers when searching for information relating to products or places, rather than using traditional printed directories. Online search engines, directories of advertisers, and the like, often charge advertisers to have listings included in a set of search results. In some circumstances, an advertiser pays for a listing or an advertisement to be displayed on a webpage that does not include a set of search results. In this case, an advertiser is charged simply for having the advertisement displayed on the webpage. Further, advertisers are often charged on a per-click basis, meaning that every time an online user clicks on an advertisement, the advertiser is charged.
From the perspective of the advertiser and from the perspective of an advertising provider, simply tracking user responses to advertisements does not always provide sufficient detail concerning a user's actions, and does not permit a fine tuning of the amount that an advertiser pays for an advertisement, or for a listing that is included in a set of search results.